bool IA_IAPI::isIPRelativeBranch() const
{
// These don't exist on IA32...
#if !defined(arch_x86_64)
return false;
#endif
Instruction ci = curInsn();
bool valid;
Address target;
boost::tie(valid, target) = getCFT();
if(ci.getCategory() == c_BranchInsn &&
!valid) {
Expression::Ptr cft = ci.getControlFlowTarget();
if(cft->isUsed(thePC[_isrc->getArch()]))
{
parsing_printf("\tIP-relative indirect jump to %s at 0x%lx\n",
cft->format(ci.getArch()).c_str(), current);
return true;
}
}
return false;
}
void IA_x86Details::computeTableAddress()
{
// Extract displacement from table insn
Expression::Ptr displacementSrc;
if(tableInsn.insn->getCategory() == c_BranchInsn)
{
Expression::Ptr op = tableInsn.insn->getOperand(0).getValue();
std::vector<Expression::Ptr> tmp;
op->getChildren(tmp);
if(tmp.empty())
{
displacementSrc = op;
}
else
{
displacementSrc = tmp[0];
}
}
else
{
parsing_printf("\tcracking table instruction %s\n", tableInsn.insn->format().c_str());
std::vector<Expression::Ptr> tmp;
Expression::Ptr op = tableInsn.insn->getOperand(1).getValue();
if(!op)
{
parsing_printf("\ttable insn BAD! (no second operand)\n");
return;
}
if(tableInsn.insn->getOperation().getID() != e_lea)
{
op->getChildren(tmp);
if(tmp.empty())
{
parsing_printf("\ttable insn BAD! (not LEA, second operand not a deref)\n");
return;
}
displacementSrc = tmp[0];
}
else
{
displacementSrc = op;
}
}
zeroAllGPRegisters z(tableInsn.addrOfInsn + tableInsn.insn->size());
displacementSrc->apply(&z);
if(!z.isDefined())
{
parsing_printf("\ttable insn: %s, displacement %s, bind of all GPRs FAILED\n",
tableInsn.insn->format().c_str(), displacementSrc->format().c_str());
return;
}
else
{
tableInsn.addrFromInsn = z.getResult();
}
parsing_printf("\ttableInsn.addrFromInsn set to 0x%lx\n",tableInsn.addrFromInsn);
}
bool IA_x86Details::isTableInsn(Instruction::Ptr i)
{
Expression::Ptr jumpExpr = currentBlock->curInsn()->getControlFlowTarget();
parsing_printf("jumpExpr for table insn is %s\n", jumpExpr->format().c_str());
if(i->getOperation().getID() == e_mov && i->readsMemory() && i->isWritten(jumpExpr))
{
return true;
}
if(i->getOperation().getID() == e_lea && i->isWritten(jumpExpr))
{
return true;
}
return false;
}
std::pair<bool, Address> IA_IAPI::getCFT() const
{
if(validCFT) return cachedCFT;
Expression::Ptr callTarget = curInsn().getControlFlowTarget();
if (!callTarget) return make_pair(false, 0);
// FIXME: templated bind(),dammit!
callTarget->bind(thePC[_isrc->getArch()].get(), Result(s64, current));
parsing_printf("%s[%d]: binding PC %s in %s to 0x%x...", FILE__, __LINE__,
thePC[_isrc->getArch()]->format(curInsn().getArch()).c_str(), curInsn().format().c_str(), current);
Result actualTarget = callTarget->eval();
#if defined(os_vxworks)
int reloc_target = current;
#if defined(arch_x86)
++reloc_target;
#endif
if (actualTarget.convert<Address>() == reloc_target) {
// We have a zero offset branch. Consider relocation information.
SymtabCodeRegion *scr = dynamic_cast<SymtabCodeRegion *>(_cr);
SymtabCodeSource *scs = dynamic_cast<SymtabCodeSource *>(_obj->cs());
if (!scr && scs) {
set<CodeRegion *> regions;
assert( scs->findRegions(reloc_target, regions) == 1 );
scr = dynamic_cast<SymtabCodeRegion *>(*regions.begin());
}
SymtabAPI::Symbol *sym = NULL;
if (scr) {
std::vector<SymtabAPI::relocationEntry> relocs =
scr->symRegion()->getRelocations();
for (unsigned i = 0; i < relocs.size(); ++i) {
if (relocs[i].rel_addr() == reloc_target) {
sym = relocs[i].getDynSym();
if (sym && sym->getOffset()) {
parsing_printf(" <reloc hit> ");
actualTarget = Result(s64, sym->getOffset());
}
break;
}
}
}
if (sym && sym->getOffset() == 0) {
// VxWorks external call.
// Need some external means to find the target.
Address found;
const std::string &sym_name = sym->getMangledName();
if (wtxFindFunction(sym_name.c_str(), 0x0, found)) {
parsing_printf(" <wtx search hit> ");
actualTarget = Result(s64, found);
// We've effectively found a plt call. Update linkage table.
_obj->cs()->linkage()[found] = sym_name;
} else {
parsing_printf(" <wtx fail %s> ", sym_name.c_str());
actualTarget.defined = false;
}
}
}
#endif
if(actualTarget.defined)
{
cachedCFT = std::make_pair(true, actualTarget.convert<Address>());
parsing_printf("SUCCESS (CFT=0x%x)\n", cachedCFT.second);
}
else
{
cachedCFT = std::make_pair(false, 0);
parsing_printf("FAIL (CFT=0x%x), callTarget exp: %s\n",
cachedCFT.second,callTarget->format(curInsn().getArch()).c_str());
}
validCFT = true;
if(isLinkerStub()) {
parsing_printf("Linker stub detected: Correcting CFT. (CFT=0x%x)\n",
cachedCFT.second);
}
return cachedCFT;
}